In the NIH/NCRR sponsored breeding programs of the National Primate Research Centers, rhesus macaques are housed in multimale-multifemale social groups in large outdoor corrals which simulates the natural social and environmental features characteristic of the species, enhancing their reproductive performance as well as their psychological well-being. Despite the importance of this naturalistic social housing, one of the most difficult problems in socially-housed macaques is their propensity for spontaneous bouts of deleterious aggression. The long-term goal of this project is to reduce the rates of deleterious aggression in captive breeding colonies of rhesus macaques. The objective of this particular application is to enhance current behavioral management techniques by developing a set of predictive models of the within group social and group-level management factors that lead to deleterious aggression and aggression-based morbidity and mortality in group-housed rhesus macaques. Multivariate statistical models using logistic normal regression and social network analysis will be developed on the longitudinal (temporal) relationship among group management factors such as age/sex composition and matriline configuration, within-group social factors such as affiliative and dominance activity patterns and levels of aggression and subsequent wounding within rhesus social groups. Our rationale is that if we gain greater insight into these social and group management factors, we will be able to identify key network measures that will allow us to prevent severe aggression events and outbreaks in the short-term and beneficial management practices that will reduce aggression-based morbidity and mortality in the long-term in rhesus macaque breeding colonies. Development of beneficial management practices that reduce aggression-based morbidity and mortality in rhesus breeding groups will contribute to public health by enhancing the health and welfare of rhesus macaques in breeding colonies that provide the animal resources critical for conducting biomedical research on nonhuman primates.